Huangqi Guizhi Wuwu decoction ameliorates myocardial damage in ovariectomized rats by regulating the structure and function of myocardial microvessels and intestinal flora

ABSTRACT Huangqi Guizhi Wuwu decoction (HGWD) is commonly used to treat cardiovascular diseases (CVDs), and HGWD could regulate intestinal flora and myocardial microvessels, this study aimed to examine whether HGWD could ameliorate myocardial damage in ovariectomized (OVX) rats by regulating the structure and function of myocardial microvessels and intestinal flora. A model of OVX rats was created, and histological examination through hematoxylin and eosin staining alongside TEM was employed to assess the microstructural lesions present in the myocardium. Myocardial microvasculature density was assessed using immunofluorescent staining. The systolic and diastolic properties of myocardial capillaries, coagulation function, blood rheology indicators, and inflammatory factor levels were evaluated. The 16S rRNA amplicon sequencing was used to detect intestinal flora in OVX rats and the intervention effect of HGWD. PICRUSt software was used to conduct a functional prediction analysis of the screened differential intestinal flora. HGWD ameliorated OVX-induced myocardium damage in rats. HGWD increased the density of myocardial microvessels and ameliorated their structural abnormalities. Additionally, HGWD maintained plasma endothelial nitric oxide synthase/endothelin-1 and prostacyclin/thromboxane balance, decreased plasma vascular endothelial-derived growth factor, thrombomodulin, endothelial protein C receptor, and von Willebrand factor levels, decreased the concentrations of serum inflammatory markers interleukin (IL) -1β and IL-6, reduced plasma viscosities, and improved the coagulation function. Besides, HGWD improved the structure and function of intestinal flora and altered significant alterations in the abundance of certain phylum and genus levels closely associated with CVD, including Actinobacteria, Ruminococcus₁, and Roseburia. HGWD alleviates myocardial damage in OVX rats, accompanied by structural remodeling of cardiac microvasculature and gut microbiota. IMPORTANCE This work elucidated the impact of Huangqi Guizhi Wuwu decoction (HGWD) on cardiac microvasculature and gut microbiota. We observed that HGWD administration ameliorated ovariectomized-induced myocardium damage. HGWD not only increases myocardial microvascular density and repairs structural abnormalities but also balances vasoactive substances, reduces inflammatory factor levels, improves blood rheology, and coagulation function. Furthermore, it reshapes gut microbiota structure and function while modulating the abundance of microbial taxa closely associated with cardiovascular diseases (CVDs). The results highlight the unique advantages of traditional Chinese medicine in regulating systemic microenvironment homeostasis, suggesting that its multi-component, multi-pathway characteristics may offer more integrative intervention strategies for preventing and managing complex metabolic CVDs.